Many Domains 1- A & C Record; Is ! Nameserver sufficient

Hello,

I may have been reading too much about setting up my DNS name server,
but haven gotten more confused, I am seeking guidance our of the forest.

Here are the details:

I have fourteen IP domains registered at a DNS registrar, an account
running on a DSL provider and a dedicated server hosted at another site.
I had built up the system over time and everything was working fine. I
had an email server (qmailrock) and web server on the system, Apache
1.3x with one host and thirteen (13) virtual hosts.

I have discontinued the dedicated server, brought the system in house to
do some development work.I have 2 static IP #'s, one dedicated to an
internal LAN/WAN and the other for the relocated server, containing the
web and email servers.

The primary and secondary name servers are hosted at the DSL's provider,
Name Server, with one A and MX record.

Previous setup: NS1.mydomain.com and NS2.mydomain.com
Current setup: NS1.dslprovider.net and NS2.dslprovider.net

I've installed qmail and Apache 2.x, both running fine, but only for the
domain with the A record at the NS1.dslprovider.net, & NS2.dslprovider.net.

Now, if I want to provide
[i] mail access
[ii] web connection

To the thirteen (13) remaining "virtual" domains do I have to set up my
own nameserver or is there a way around it?

Should these be NS3.mydomain.com & NS4.mydomain.com ?
Is there some recommended instruction set for doing this, BIND9 and
named server, alone? any registration ? can it be run on the same web
and email server? ...

I can set up virtual domains in the apache http.conf files, but a client
pointing the appropriate URL does not see it because there is no A
record pointing to it.

Secondly, for the mail there is no C record either

Am I correct and what would be a recommended solution.


Thanks!